The present invention relates to nitrogen-containing monoterpene derivatives, especially, to novel nitrogen-containing monoterpene derivatives having a pyrindine skeleton synthesized by, for example, substitution of an oxygen atom in a iridoid skeleton for a nitrogen atom.
Various studies have been directed toward nitrogen-containing monoterpene derivatives having a pyrindine skeleton and processes for synthesizing these derivatives have already been reported. However, none of these processes utilizes the process of this invention wherein an oxygen atom in n iridoid skeleton is replaced with a nitrogen atom. It has been known that iridoid glycosides and aglycones occur in plants, for example, in large amounts in Gardenia jasminoides Ellis, Genipa americana L. etc. of Rubiaceae. It has been said that Gardenia jasminoides Ellis exhibits physiological activities such as purgative, antidotal and antiinflammatory effects and that Genipa americana L. exhibits an antituberculosis effect. The inventors have disclosed that aglycones of irodoid glycosides react with primary amino group-containing substances to form dyestuffs (Japanese Patent Application Nos. 77136/1974 and 130131/1975). However, the chemical structures of components constituting the dyestuffs have not yet been elucidated. The inventors have perfected the present invention upon conducting further investigations on the properties of iridoid glycosides and aglycones thereof and also on the products of reaction of iridoid glycosides or their aglycones with primary amino group-containing substances.